【作者】 顾燕；

【导师】 沈连丰；

【作者基本信息】 东南大学 ， 通信与信息系统， 2006， 博士

【摘要】 移动Ad Hoc网络无需固定基础设施的支持,具有组网方便快捷、可靠性高、灵活性强等优点,其应用越来越广泛。随着各种智能化、小型化的无线终端和智能家庭终端大量出现,它们之间的信息共享和数据交换需求极大地推动了移动Ad Hoc网络的发展,使Ad Hoc网络成为当前研究的热点之一。在此背景下,本论文对移动Ad Hoc网络中的信道接入和共享问题、功率控制和能量保护问题以及路由问题进行了深入研究。论文首先对Ad Hoc网络的媒体接入控制技术进行研究,分析了信道的多跳共享性及隐藏终端问题和暴露终端问题,提出了一种新的双信道协议,采用双信道传输以及改进的握手协议和信道预留方法避免了数据冲突,有效减轻了隐藏终端和暴露终端对数据传输的影响,提高了信道利用率。节点根据收到的不同的控制包,在控制信道和数据信道中采取3种不同的预留方法。在数据传输中,隐藏终端能够同时接收数据,暴露终端能够同时发送数据。在高业务量网络中分析了该协议的信道吞吐量属性,通过与基于RTS/CTS的协议的比较,结果表明,该协议能有效提高Ad Hoc网络的信道吞吐量。其次,论文对Ad Hoc网络中的功率控制问题进行深入分析,提出了一种功率控制MAC协议,在控制包中包含发送功率和容许接收功率,通过两个通信节点之间的控制信息的交换来决定数据包的发送功率和限制其他邻节点的发送功率,有效降低隐藏终端和暴露终端之间的干扰,并且在数据接收的同时允许邻节点同时发送信息。通过仿真与IEEE 802.11的MAC协议进行比较,结果表明,在移动自组织网络中,该功率控制协议能够提高系统的端到端吞吐量性能,而大大减少移动节点的功率消耗,因此节约了网络总功率消耗。然后,本论文对移动自组织网络中的节点能量均衡问题进行深入研究,提出了一种利用节点剩余能量信息进行路由选择和路由维护的能量平衡路由协议。在路由发现过程中选择节点能量充足的路由,在节点剩余能量低于某一阈值时,向上行节点发出警示信息,使其提前更换或寻找新的路由,避免了因节点能量耗尽而引起的路由中断,减少了路由修复。通过仿真与DSR路由协议相比较,结果表明,在节点能量受限的移动自组织网络中,该能量平衡路由协议提高了节点的能量利用效率,延长了Ad Hoc网络的生存时间,减少了网络传输中的丢包数,并提高了网络的吞吐率属性。最后,论文对Ad Hoc网络中的能量保护问题进行分析,提出了一种能量有效的跨层协议,将网络层的能量感知路由与MAC层的功率控制技术相结合,以提高节点的能量利用效率。在网络层中根据节点剩余能量决定节点接入路由的延迟时间,从而使剩余能量较多的节点能够更快地接入路由,以使网络中的能量消耗更公平。在MAC层中实现功率控制,减少节点的实际能量消耗。仿真结果表明,在移动自组织网络中,该跨层更多还原

【Abstract】 Mobile Ad Hoc network (MANET) has some advantages such as convenient and quick network setup, high reliability, strong flexibility, without depending on any fixed supporting infrastructure. These advantages make the applications of Ad Hoc network very extensive. With the appearance of numerous intelligentized and miniaturized wireless devices and smart household terminals, their requirements of information share and data exchange accelerate the development of Ad Hoc network and make it one of the current research hotspots. The research of channel access and share, power control, energy protection and routing in mobile Ad Hoc networks are focused on in this dissertation.Firstly, the protocol of medium access control (MAC) in Ad Hoc networks is researched. The multi-hop sharing character of wireless channel, the hidden terminal and exposed terminal problems are analyzed, and a novel dual channel protocol is presented. In this protocol, dual channel and improved handshakes as well as channel reservation are employed to avoid collision in data transmission. The hidden terminal and exposed terminal problems during data transmission are alleviated and the channel utilization ratio is increased. Based on received control packets, nodes use 3 different Network Allocation Vectors (NAV) in control channel or data channel. During data transmission, the hidden terminal can receive data simultaneously and the exposed terminal can also transmit data. The channel throughput performance of the protocol is analyzed and evaluated in heavy traffic networks. A comparison with a RTS/CTS based protocol is given. The results show that the protocol can improve channel throughput in Ad Hoc networks.Secondly, the problem of power control in Ad Hoc networks is analyzed and a power controlled MAC protocol based on IEEE 802.11 is presented. Transmission power and permitted receiving power of messages are comprised in the control packets. By exchanging control information between a pair of communication nodes, their transmission power of data packet is determined and the transmission power of other neighbor nodes is also restricted, which can effectively reduce the interference between hidden terminals and exposed terminals. During data receiving of one node, the protocol also allows its neighbor nodes to transmit. It is compared with the IEEE 802.11 MAC protocol by simulation. The results indicate that the power controlled protocol proposed can improve the end-to-end throughput performance in mobile Ad Hoc networks, while decrease the power consumption of mobile nodes greatly.更多还原